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1,3 1 1 793.. Patented July '29, 1919.

L. L. DRIGGS.

PEBCUSSION FU.S E FOR'SHELLS. APPLICATION HLEDIJAN. 2. i917.

, UNITED, srerns PATENT OFFICE.

LoUIs L. DRIGGS, or NEW 1103K, 1v. Y.

rnnoussroiv-rnsn Eon snEnLs.

To all whom it may concern:

Be it known that I, LoUIsL. Dnrecs, a citizen of the United States, residing at New York, in the county of New York and State of New York, have invented certain new and useful Improvements in Percussion- Fuses forShells and I do hereby declare the following-to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

My present invention relates to improvements in percussion fuses for shells, and it is more especially intended for use with shells containing high explosives, such as picric acid, or trinitrotoluol. A

Such shells are generally, provided With rather thin, but very strong, walls and contain a large charge of high explosive. In ,orde'r to detonate the bursting charge something more powerful than the regular percussion fuse is necessary; consequently the fuse is provided with a larger ignition charge which is connected to one ormore tubes containing gun cotton and trinitrotoluol, or other suitable explosive, which are first detonated and cause the detonation of v the high explosive bursting charge. 7

My invention is also intended to provide an absolute safety lock to prevent the percussion fuse from being prematurely exploded, as from accidentally dropping-the shell, or rough and careless handling thereof; and at the same time to provide an arrangement by which the locking means for normally holding the plunger in the safety position are held out of engagement with said plunger after the shell has acquired sufficient rotary velocity, such, forinstance, as

that imparted to it by passing through the rifled bore of a gun.

My invention will be understoodby reference to the accompanying drawings, in

which the same parts are indicated by the samereference symbols throughout the several views, and in which Figure 1 shows a central longitu d nal section through the fuse stock and connected parts, the plunger and spring clip being shown in elevation;

Fig. 2 is an end view of the plunger as seen from the front thereof;

Fig. 3 shows a section along the line"3 3 of Fig. 2;

i .4 is a detail showing perspective ries the firing point 11, and the rearwardly extending to this central portion Specification of Letters Patent. Patented July 29, 1919 Application filed January 2, 1917. Serial No. 140,182.-

the spring clip holding the plunger in place; and V Fig. 5 shows the automatic catch for holdingthe spring clip locked out of engagement with theplunger after the shell has acquired the rotary velocity due to being fired from the gun. Y

1 represents the fuse stock, which also forms the nose of the projectile. Mounted in the forward portion of the chamber of the fuse stock is the primer block 2, chambered, at this forward portion, as at 3 to hold the charge 4: of quick burning powder, the rear end of which chamber is closed by the thin disk 5, of oiled paper, or other suitable material, which disk masks the perforaher 9, in which the body portion 10 of the plunger slides freely and longitudinally through a short distance. The plunger caris provided with v stem 12, flanged as at 13. The opposite sides of-the plunger are provided wit parallel grooves 14, adapt ed to receive the resilient arms of the spring clip, as will be hereinafter described, and

the plunger is also provided with passages 15, extending outward at either side of the firing point 11, and opening interiorly into the axial bore 16 through the stem of the plunger; thusJE I'JniI g a Y-sha. ed channel for the passage through the plunger of the ignition charge from the primer 2 and the chamber 3.

The plunger is normally held in the safety position by'the spring clip shown in 4:, which comprisesthe central portion 17 connected to the primer block 2, and provided with an opening l8 for the passage therethrough ofthe firing point 11., Connected are the resilient arms 19, each terminating in a weight. 20, in the form of a segment of a cylinder, as shown most clearly in Fig. 4. These weights may be integral with, or attached to the resilient arms 19, and normally grip the stem of the plunger holding it against forward movestock is provided with the cylindrical chamresilient catches 21 on the ring 22, lock the spring clip in the distended position, leaving the plunger free to fly forward when the flight of the shell is suddenly arrested, as by striking the ground, the target, or any other solid object.

This arrangement provides a perfectly safe lock for the plunger, except after the shell has been spun up, and positive lock to keep the spring clip out of engagement after the fuse has been primed automatically by firing the projectile from the gun.

When the plunger is in the safety position, shown in Fig. 1, these catches 21 project into notches 13 in the flange 13 of the plunger.

In rear of the plunger I provide in the fuse stock the screw plug 23, which is preferably chambered in its forward portion and provided in the rear with a head 24:, perforated as at 25 to permit the passage of the flame from the igniter rearward. This opening may also be closed by a small disk 26, let 1nto a groove 27.

This plug 23 is provided with sockets 28 so it may be conveniently screwed in place by means of a spanner. In rear of the screw plug 23, I provide a closed tube 30, screwed at its forward end into the fuse stock as at 31, and its rear end is closed as by the screw plug 32, which is preferably recessed on its forward face, as at33, to enlarge the capacity of the chamber 3% which is provided in the body portion of the tube 30 for the reception of the detonating charge for the high explosive in the shell. This chamber 34: is constricted at its forward end, and is closed by the screw plug 35 in place in the forward end of the tube, as by means of a spanner engaging the sockets 36.

This screw plug 35 is provided with a chamber 37 inclosing an ignition powder charge, which chamber 37 is closed at its rear end by the disk 38 engaging in the undercut groove 39, and at its forward end is closed by the disk 40. The chamber 34 will be normally filled with the detonating charge, not shown, which; is omitted for the sake of clearness in the drawings.

The operation of the device is as lows When the projectile is fired from the gun, the rifling will impart to it a spinning motion which will throw out the weights 20, releasing the engagement of, same with the stem of the plunger, so that the plunger is free to fly forward when the forward movement of the projectile is suddenlv arrested. These weights as they fly outward under the centrifugal force, press back the spring catches 21 which engage the weights after they have sprung outward under the action of centrifugal force, locking the weights 20 yet provides a which is screwed 7 and the arms 19 in the distended position shown in dotted lines in Fig. 1; and thus positively holding these arms in the disengaged position, so that the plunger is at all times free to fly forward. In this way the plunger is free to act even if the rotary velocity of the shell falls so low that the spring arms would tend to overcome the centrifugal force, and would normally restore the weights to the locking position, as shown in full lines in Fig. 1.

The spring clip being thus held in the disengaged position, when the shell strikes the ground, or other target, the plunger flies forward, explodes the primer, and thus fires the charge t, and the flame blows back through the passages 15 and 16 in the plunger, and the pressure displaces the disks 26 and 4:0, and ignites the powder charge in the chamber 37, blowing out the disk 38 and exploding the detonating charge in the chamber 5. This detonating charge will explode the high explosive bursting charge of the shell.

It will thus be seen that I provide a positively safe fuse which can only be thrown into the operative position when the shell has imparted to it a sufficient rotary velocity, such as will be given to it by the passage through the bore of the gun; but the spring clip controlled by this rotary velocity is positively and automatically locked against springing back into the engaging position, so that the plunger is always free to act after the fuse has once been primed.

The plunger is made comparatively heavy and short, so that should the shell strike sidewise, or even rear end first, as sometimes happens when a shell tumbles, the.

plunger would still rebound and strike the i primer, exploding the charge.

It will be obvious that various modifications might be made in the herein described device, and in the construction, combination and arrangement of parts which could be used without departing from the spirit of my invention.

Having thus described my invention what I claim and desire to secure by Letters Patent of the United States is 1. The combination with a fuse stock and a tube connected to the base thereof, with a detonating charge carried in said tube, of a primer carried in said fuse stock, one or more chambers containing powder adapted to be ignited by said primer, and con nected with said tube, a plunger adapted to explode said primer, a spring clip having weighted resilient arms normally locking said plunger in the safety position but thrown out of engagement therewith when the shell is spun up, and automatic means for locking said spring clip in the disengaged position after it has been acted upon by centrifugal force, comprising inclined spring catches adapted to be pressed backward by said weighted arms as they are thrown outward by centrifugal force but to lock said arms against returning inward when said centrifugal force decreases, due to the slowing down of the rotary motion of the projectile, substantially as described.

2. The combination with a fuse stock and a tube connected to the base thereof, with a detonating charge carried in said tube, of a primer carried in said fuse stock, one or more chambers containing powder adapted to be ignited by said primer, and connected with said tube, a plunger adapted to explode said primer, a spring clip having weighted resilient arms normally locking said plunger in the safety position but thrown out of engagement therewith when the shell is spun up, and automatic means for locking said spring clip in the disengaged position after it has been acted upon by centrifugal force, comprising a ring provided with inclined spring catches projecting forwardly and at an angle and adapted to be pressed backward by said weighted arms as they are thrown outward by centrifugal force but to lock said arms against returning inward when said centrifugal force decreases, due to the slowing down of the rotary motion of the projectile, substantially as described. 3. The combination with a fuse stock and a tube connected to the base thereof, with a Copies of this patent may be obtained for five cents each, by addressing the detonating charge carried in the main body of said tube, and an ignition charge carried in the front end of said tube, of a primer carried in said fuse stock, a chamber located in front of said primer and containing powder adapted to be ignited by said primer, a plunger adapted to explode said primer, the said plunger being provided with a body portion, a firing point, and a stem, with a channel through said body portion and stem for the passage rearward therethrough of the flame from said primer and powder chamber, the said passage through the plunger carrying the flame to the ignition charge in the forward end of said tube, a spring clip having weighted resilient arms normally locking said plunger in the safety position but thrown out of engagement therewith when the shell is spun up, and automatic means for locking said spring clip in the disengaged position after it has been acted upon by centrifugal force, comprising inclined spring catches adapted to be pressed backward by said weighted arms as they are thrown outward by centrifugal force but to lock said arms against returning inward when said centrifugal force decreases, due to the slowing down of the rotary motion of the projectile, substantially as described.

In testimony whereof, I aflilx my signature.

LOUIS L. DRIGGS.

Commissioner of Patents,

Washington, D. 0. 

